Preheat oven to 400°F/200°C and place oven rack in center. Line a large baking sheet/tray with parchment paper.

Line the slices on the baking pan evenly apart. Bake for 5 minutes. Allow to cool on the pan, they crisp more as they cool.

Add the oil to a large heavy saucepan with lid or Dutch oven over medium heat. Add the kernels and stir to coat them all in the oil and make sure they are in an even layer. If the bottom of your pan is smaller and you can’t get them in a single layer, work in batches. 

Place the lid on the pan leaving a small gap to allow steam to escape. Once they start popping, listen for the popping to speed up. Shake the pan slightly halfway through to ensure even popping. When you start to hear the popping slow down, turn off the heat. When the popping has completed stopped, remove lid so no moisture gets on the popcorn as this can make it soggy or chewy. Pour into your serving bowl.

To a small pan add the butter and melt over medium-low heat. Once melted add the garlic cloves and allow the garlic to cook in the butter with the garlic for 5 minutes, to infuse the butter with flavor. Do not brown the garlic. Skim some of the white foam off the top. This is the milk solids so you’ll be left with clarified butter. Once the butter is fragrant and you can smell the garlic, remove the cloves. Save them for use in another recipe.

Turn off the heat and stir in the dried basil.

Drizzle the popcorn with half the butter, then toss to coat. Repeat with the rest of the butter. Top with the grated Parmesan cheese and crumble the prosciutto over the top.